Coating composition and paper material coated therewith



Patented Nov. 20, 1923.

or paras;

at HQ,

WILBUR L. WRIGHT, 0F FULTON, NEW YORK.

COATING COMPOSITION AND PAPER MATERIAL COATED THEREWITH.

No Drawing. Application filed May 21,

To all whom it may concern:

Be it known that I, WILB UR L. WRIGHT, a citizen of the United States of America, and resident of Fulton, Oswego County, State of New York, have invented certain new and useful Improvements in and Relating to Coating Composition and Paper Material Coated Therewith, of which the following is a specification.

This invention relates to certain improve- Inents in the art of rendering paper material and the like grease and moisture proof; and the objects and nature of the invention will be readily understood by those skilled in the art in the light of the following explanation of what I now believe to be preferred expression and embodiment of. my invention.

An object of the invention'is to provide paper material embodying a greaseproof barrier that will also act as a barrier against passage of moisture, and to provide a composition for forming such barrier.

With these and other objects in view my invention embodies paper material impregv nated or coated with a composition insoluble in grease, and that will also serve as abarrier against passage of moisture, and also a composition for grease and water proofing paper material and the like;

My invention, broadly contemplates subjecting any suitable greaseproofing body or composition to the action of somes1 1itable agent that will act to so bind together or consolidate the greaseproofing substance on or in the paper material as to render such sub; stance capable of resisting the passage of 'moisture as well as grease from one side of the paper material to the other. 7

I prefer to accomplish this Water proofing result by the astringent action of some suitable agent such as tannin or tanic acid, although approximately the same result can be accomplished by the coagulating action of a suitable coagulant, for instance, such as acetic acid. The astringent acts to bring the composition and the fibers into such close relation as to prevent passage of moisture and the coagulant acts to bind molecules and fibers together and render the barrier insoluble in water, and hence both gain paper material the same end, i. e., render the impervious to moisture.

My invention is applicable to various papermaterial grease-proofing compositions par- .ers for food-products.

1920. Serial No. 383,166.

ticularly those comprisin an adhesipe, gelatinous or body forming sblution embodying one or more ingredients to maintain the flexibility of the'coating or filling formed on or in paper material by the application of the composition thereto.

Such compositions can comprise a solution of casein, gelatine or other suitable adhesive, and glycerine or an emulsified oil usually a vegetable oil. Where gelatine is employed the gelatine and ble oil) are. dissolved in sulting composition is applied hot to the paper material to form a flexible coating thereon that acts as a barrier against the passage of grease; The ingredients can be employed in approximately the proportions of gelatine from two to three hundred parts more or less; glycerine or oil from ten to one hundred parts more or less, and water somewhere about one thousand parts more or less.

the proportion will be about as above, but a suitable alkali or the like such as ammonia will be added to aid in dissolving the casein. The composition embodying casein can be aplplied to the paper material either hot or co Other ingredients can be included to perform added functions in the composition.

These compositions are usually applied in any suitable manner or by any suitable means to form coatings on the inner surfaces of paper containers, for instance, contain- The compositions can also be added to the aper stock or fibrous material in the process of making paper, so that the finished paper will be impregnated with a'fiexible body that'forms a barrier against passage of grease.

Such grease barrier forming flexible bodies or coatings, however, are generally soluble in water, and it is the purpose of my inglycerine (or soluwater and the re r Where caseinis used instead of gelatine, v

vention to so chan the nature thereof (wheth or formed by the composition hereinbefore noted or by other compounds) as to A the passageof moisture.

This result can be attained'bv adding a suitable proportion of tannin (tannic acid) to the com osition, orother astringent suitable for the uroose. For instance, "I usually add about three per cent (more or less) enable such bodies to act as barriers against of tannic acid to the grease proofing compoter of Waterproofing the grease proof barrier, is attained by subjecting the grease proofed paper containers (or the paper material) to acetic acid fumes. In other Words, after the paper material or the papercontainers have been coated with the grease proofing composition, such treated paper material or containers are placedin a closed chamber and subjected to the action. of

acetic acid fumes for a suitable length of time, say for about thirty minutes. The acetic acid solution in the chamber (out of contact with the paper material and cont ainers) is usually subjected to heat to accelerate the generation of fumes. This acid acts on the grease proof coating as a coagulant to render the same insoluble in Water.

While I have given examples of grease proofing compositions, .yet I do not Wish to limit my invention to the particular compositions named as I Wish to broadly claim my invention in connection with all paper and like material grease proofing compositions and coatings or bodies to which it is applicable.

What I claim is 1-- j 1. A paper container for food products having an interior flexible grease proof coating coagulated to render thesame moisture proof.

2. A paper container barrier formed by a casein solution moisture proof by acid.

3. A aper material container embodying a flexible grease proof barrier coagulated by acid to render the same moisture proof.

I 4. A. paper-material container embodying a flexible grease proof barrier rendered moisturf1 proof by a small percentage of tannic aci embodying a grease WILBUR L. WRIGHT.

rendered 

